In an automotive transmission, a selectable one-way clutch (SOWC) is a torque transfer mechanism that is capable of producing a mechanical connection between a driving member of the transmission via a rotatable input race or a first coupling plate of the SOWC, and an independent driven member of the transmission via an output race or second coupling plate of the SOWC, in one or both rotational directions. A SOWC can overrun in one or both directions of rotation depending on its particular design. Typically, a SOWC contains a selector device, such as a selection ring or a slide plate, the movement of which selects the operating mode of the SOWC.
The mechanical means used to lock a SOWC are varied. For example, a SOWC can use rollers, sprags, rockers, struts, or another suitable torque-transmitting element, a plurality of which are positioned between the input and output races of the SOWC. Depending on the particular type or style of SOWC used and the required direction of rotation and torque holding, each race may contain unique surface features, such as windows or strut wells, each being suitable for engaging one or more of the torque-transmitting elements positioned therein in order to selectively enable various clutch operating modes.